Wind-driven evolution of the North Pacific subpolar gyre over the last deglaciation

Gray, W. R., Wills, R. C. J., Rae, J. W. B., Burke, A., Ivanovic, R. F., Roberts, W. H. G., Ferreira, D. ORCID: https://orcid.org/0000-0003-3243-9774 and Valdes, P. (2020) Wind-driven evolution of the North Pacific subpolar gyre over the last deglaciation. Geophysical Research Letters, 47 (6). e2019GL086328. ISSN 0094-8276 doi: 10.1029/2019GL086328

Abstract/Summary

North Pacific atmospheric and oceanic circulations are key missing pieces in our understanding of the reorganisation of the global climate system since the Last Glacial Maximum (LGM). Here, using a basin-wide compilation of planktic foraminiferal δ18O, we show that the North Pacific subpolar gyre extended ~3 degrees further south during the LGM, consistent with sea surface temperature and productivity proxy data. Analysis of an ensemble of climate models indicates that the expansion of the subpolar gyre was associated with a substantial gyre strengthening. These gyre circulation changes were driven by a southward shift in the mid-latitude westerlies and increased wind-stress from the polar easterlies. Using single-forcing model runs, we show these atmospheric circulation changes are a non-linear response to the combined topographic and albedo effects of the Laurentide Ice Sheet. Our reconstruction suggests the gyre boundary (and thus westerly winds) began to migrate northward at ~17-16 ka, during Heinrich Stadial 1.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/87821
Item Type	Article
Refereed	No
Divisions	Science > School of Mathematical, Physical and Computational Sciences > Department of Meteorology
Publisher	American Geophysical Union
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